My date had a few bones to pick with it but overall we were very entertained.
For one we could definitely tell the difference in directing. The choice of shots was rather different from the previous movies, and it just didn't have that "magical" feel they did.
There IS confusing parts in the movie. But it all becomes clear eventually. It's really not that hard a movie to follow.
Dumbledore's actor apparently changed, too. I didn't even notice; I guess I'm not a stickler for those things. Heh.